1. Field of the Invention
The present invention relates to a character processing apparatus having the function of converting data such as characters or the like coded in a vector form into a dot form.
2. Related Background Art
Hitherto, when data in a vector form is converted into data in a dot form, if the data consists of one character, the data is converted in a lump into the data in a dot form in a memory.
However, if the capacity of the memory is limited, vector data exceeding a matrix in the memory cannot be converted into dot form data.
On the other hand, in the case of an output device such as a thermal copy transfer type printer or the like which prints data line by line, after one character is converted into a dot form as a whole, it is output to the output device. Therefore, there is a problem that when data is output to the printer, it takes a long waiting time at the initial stage.
Hitherto, in the case where data in a vector form is converted into data in a dot form and is output to a line output type output device such as a thermal copy transfer printer or the like, the vector data is converted into the dot data character by character, or a data buffer is provided and the data is stored to the data buffer and is then converted into the dot form data.
However, in the former case, there is a problem that in order to output the data to the line output type output device, if data of one line has been output, no more data is in storage, and more data must be read out from the beginning and must be converted. This, takes a long processing time. In the latter case, there occurs a problem that, unlike dot form data , the size of the data in the vector form changes depending on the kind of font, so that the number of characters which can be stored is determined by the maximum data amount and the characters beyond such a predetermined number cannot be converted into data in the dot form. There is also a problem that since the number of storable characters is determined by the maximum data amount, the amount of unusable data increases.
Hitherto, when data in the vector form is converted into dot form data, all dot form data is formed in a row (for instance, in the row direction shown in FIG. 4) from the data in the vector form irrespective of the output device. One type of output device processes the data in the dot form in the row; another type of output device processes the data in the dot form in a column (for instance, in the column direction shown in FIG. 5). Therefore, in the conventional apparatuses, since the conversion from row to column must be executed as necessary on the output device side, there are problems that the required program size increases and that it takes a long processing time. On the other hand, in dependence on the band width which is required by the output device or characters, there is an output device with which the processing time becomes short if the painting process when the vector data form is converted into the dot data is executed in rows or an output device such that the processing time becomes short when the painting process is executed in column. Therefore, there is a problem such that if all of the processes are set to the same process, the processing time becomes long.
Hitherto, when vector data is converted into dot data, there has been proposed a method whereby the dot data is formed from the vector data while inverting the contents of the memory using the NOT of the logic operation (Japanese Patent Application 63-210450).
However, in the case of the above example, since the contents of the memory are inverted by the NOT, as shown in FIG. 1, no process is executed to the lateral line of a character, that is, the line segment whose Y coordinate does not change as shown in FIGS. 1A and 1B. Therefore, the size (width) of the lateral line becomes uneven in the cases of (a) (width W) and (b) (width W') or the lateral line is extinguished. Thus, there is a problem such that in the case of generating a small character, the character quality deteriorates.
FIG. 2 is a diagram showing an example in which vector data was converted into dot data. The lateral lines at positions shown by reference numerals 100 and 200 are extinguished.
In a manner similar to the above, there is also a problem such that the quality of figures or characters deteriorates.
According to the conventional technique, for instance, as disclosed in JP-B-53-41017, the character or the like which was coded by a stroke display method is converted into a dot display signal and, further, all of the signals between the "1" signal of the line output and the "1" signal are converted into "1" by a converting circuit and the high quality character signal of the dot display type is generated.
However, in the conventional example, since all of the signals between the "1" signal of the line output and the "1" signal are converted into "1", in order to express the frame line of a blank character by n dots from the signals, as shown in FIG. 30, the frame line is shifted by n bits with respect to the direction of the line output and the exclusive OR of the shifted data and the data before it is shifted must be calculated.
With respect to the value of n mentioned above, as the resolution of the output device such as printer, display, or the like rises, the output result becomes obscure when the value of n is small. Therefore, it is necessary to increase the value of n when the resolution of the output device rises. However, when the value of n increases, the line must be shifted by only the increased amount and there is a problem such that it takes a long processing time.